The present invention is directed to a method for splicing two textile yarns, and to apparatus for performing this method.
Methods for splicing two textile yarns are known in which a beard is formed on each yarn end to be spliced by untwisting a portion of this end, with the beard fibers being mutually separated at zones or areas of the beard bases, and the separated fibers of both ends being mutually superimposed by arranging the fiber ends of one beard at the beard base of the opposite beard and intertwining or interpenetrating the fibers of both beards, with yarn torsion being simultaneously transferred to the mutually interpenetrated or intertwined fibers from both ends of each beard.
EP Pat. No. 81-29,808 has previously suggested splicing textile yarns by forming a beard on both yarn ends to be spliced with the beard bases being in spaced apart relation, then placing one beard upon the other in a plane and with the ends of one beard facing the base of the other beard respectively, and then making the fiber ends of the respective beards penetrate between the separated fibers at the adjacent bases of the other beard. When a yarn twist is reinserted in the beards, the thus-arranged fibers reassume the original conditions of the spun yarn, appreciably unchanged, in appearance or in mechanical strength of the yarn.
The method according to this patent requires a comparatively complex mechanism for forming the beard on a flat surface and carrying out the interpenetration or intertwining of the end fibers at the respective spaced-apart zones of the adjacent beards. In fact, this method requires for forming the beards, a mechanical device for forming the beard itself, a mechanical device for untwisting the yarn, pneumatic, electrostatic, and thermal devices for extending the fibers in a plane and separating the same at the base zones for individuating the fibers, as well as forcing the beard fibers to mutually separate away thus providing a combing effect, and air injection ducts which are transversely directed in the plane of the beards. Other devices are also used, such as a device for suctioning through the beard-supporting platen to accommodate or support the beard, or a device for applying hot air for enhancing the fiber plasticity.
Furthermore, when pneumatic, thermal, or electrostatic devices are resorted to, consistency of results is not thoroughly controllable and partially depends on the nature of the yarns to be spliced. In fact, due to the nature of the yarn, the pneumatic, electrostatic and thermal devices do not always result in obtaining beards showing the same features or characteristics.
U.S. Pat. No. 4,244,169 and EP Pat. No. 53,093 are variations of EP Pat. No. 81-29,808. Use is made of ultrasound in EP Pat. No. 53,093 for individuating the fibers.
Other documents describe particular devices for untwisting the yarns, such as applications EP Pat. No. 39,609; EP Pat. No. 78,776; EP Pat. No. 123,329; EP Pat. No. 134,764; EP Pat. No. 78,777; EP Pat. No. 78,778; EP Pat. No. 120,523; and EP Pat. No. 140,412, in which the yarn is untwisted by making it roll between two surfaces moving in opposite directions. These surfaces are basically formed of discs movable at an angle.
Pneumatic devices for imparting a twist to a yarn, either in the spinning process or in the course of the yarn splicing operations, are also well known.
Swiss patent specification No. 495,445 describes a method for joining two yarn ends by means of a pneumatic chamber, in which the two yarn ends are inserted and mutually adhere under a twist imparted by the pressurized air spinning or revolving within the chamber in a single direction.
German patent specifications Nos. 2,750,913 and 2,854,514 describe a method for joining two spun textile yarns by means of a device having a turbulence chamber causing a twist effect to take place, when each yarn end is wound about the other end.
In the above methods and devices, both yarn ends are inserted in the pneumatic chamber in superimposed condition.
In the spinning method called "Open End", use is made of two chambers, each one of which causes pressurized air rotation in opposite directions.
While the results obtained with the method generally described above are indeed good, the means used for carrying out the same into practice give rise to problems and lead to comparatively costly and complex solutions.